Adds an annotation, `DoNotAddImportsAnnotation` that prevents AbstractImportsAdder from adding imports.
Fixes #8257

Concatinate contiguous strings when converting from concatination to interpolated string
fixed #16820

This project is no longer necessary.  It used to help us get TDD working fine in Visual Studio.  That's no lonegr needed with the recent build cleanup.  TDD still functions with this project removed.

Calling Wait() on a task means it will block the current thread until
    the underlying task is complete, however that task may still run on a
    background thread.  We are seeing an error where the async method is
    being scheduled to a background thread when we try and commit an edit to
    the buffer.  Edits to the buffer can only be made from the UI thread so
    exceptions are thrown.

    The simplest fix here is to not make the method async at all.